If you are wondering why all of the questions all of a sudden...My family and I are going on a 17 day vacation..starting in Florida at the beaches for 2 days, Disney for 7 days, then up to Atlanta for a few days, Biloxi, MS for a day, then Texas for 4 days. I plan on doing a lot of photographing during this time and there are going to be circumstances that I have never encountered before. The question I have for the ISO setting is due to the Safari tour at the Animal Kingdom. I always shoot at ISO 200, but I am wondering if I should boost that up to 400 or 800 because we will be in a moving vehicle and I am sure that some of the animals will be moving around as well. Will this help or should I just stay at ISO 200 and home my telephoto lens is fast enough?